2 * Copyright (c) 1997, 1998 Justin T. Gibbs.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions, and the following disclaimer,
10 * without modification, immediately at the beginning of the file.
11 * 2. The name of the author may not be used to endorse or promote products
12 * derived from this software without specific prior written permission.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
18 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * $FreeBSD: src/sys/i386/i386/busdma_machdep.c,v 1.94 2008/08/15 20:51:31 kmacy Exp $
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/malloc.h>
34 #include <sys/thread2.h>
35 #include <sys/bus_dma.h>
36 #include <sys/kernel.h>
37 #include <sys/sysctl.h>
39 #include <sys/spinlock2.h>
42 #include <vm/vm_page.h>
44 /* XXX needed for to access pmap to convert per-proc virtual to physical */
47 #include <vm/vm_map.h>
49 #include <machine/md_var.h>
51 #define MAX_BPAGES 1024
62 bus_dma_filter_t *filter;
70 bus_dma_segment_t *segments;
71 struct bounce_zone *bounce_zone;
75 * bus_dma_tag private flags
77 #define BUS_DMA_BOUNCE_ALIGN BUS_DMA_BUS2
78 #define BUS_DMA_BOUNCE_LOWADDR BUS_DMA_BUS3
79 #define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4
81 #define BUS_DMA_COULD_BOUNCE (BUS_DMA_BOUNCE_LOWADDR | BUS_DMA_BOUNCE_ALIGN)
83 #define BUS_DMAMEM_KMALLOC(dmat) \
84 ((dmat)->maxsize <= PAGE_SIZE && \
85 (dmat)->alignment <= PAGE_SIZE && \
86 (dmat)->lowaddr >= ptoa(Maxmem))
89 vm_offset_t vaddr; /* kva of bounce buffer */
90 bus_addr_t busaddr; /* Physical address */
91 vm_offset_t datavaddr; /* kva of client data */
92 bus_size_t datacount; /* client data count */
93 STAILQ_ENTRY(bounce_page) links;
97 STAILQ_ENTRY(bounce_zone) links;
98 STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
99 STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
101 struct spinlock spin;
112 bus_size_t alignment;
116 struct sysctl_ctx_list sysctl_ctx;
117 struct sysctl_oid *sysctl_tree;
121 #define BZ_LOCK(bz) spin_lock(&(bz)->spin)
122 #define BZ_UNLOCK(bz) spin_unlock(&(bz)->spin)
124 #define BZ_LOCK(bz) crit_enter()
125 #define BZ_UNLOCK(bz) crit_exit()
128 static struct lwkt_token bounce_zone_tok =
129 LWKT_TOKEN_INITIALIZER(bounce_zone_token);
130 static int busdma_zonecount;
131 static STAILQ_HEAD(, bounce_zone) bounce_zone_list =
132 STAILQ_HEAD_INITIALIZER(bounce_zone_list);
134 int busdma_swi_pending;
135 static int total_bounce_pages;
136 static int max_bounce_pages = MAX_BPAGES;
137 static int bounce_alignment = 1; /* XXX temporary */
139 TUNABLE_INT("hw.busdma.max_bpages", &max_bounce_pages);
140 TUNABLE_INT("hw.busdma.bounce_alignment", &bounce_alignment);
143 struct bp_list bpages;
147 void *buf; /* unmapped buffer pointer */
148 bus_size_t buflen; /* unmapped buffer length */
149 bus_dmamap_callback_t *callback;
151 STAILQ_ENTRY(bus_dmamap) links;
154 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist =
155 STAILQ_HEAD_INITIALIZER(bounce_map_callbacklist);
157 static struct bus_dmamap nobounce_dmamap;
159 static int alloc_bounce_zone(bus_dma_tag_t);
160 static int alloc_bounce_pages(bus_dma_tag_t, u_int, int);
161 static int reserve_bounce_pages(bus_dma_tag_t, bus_dmamap_t, int);
162 static void return_bounce_pages(bus_dma_tag_t, bus_dmamap_t);
163 static bus_addr_t add_bounce_page(bus_dma_tag_t, bus_dmamap_t,
164 vm_offset_t, bus_size_t);
165 static void free_bounce_page(bus_dma_tag_t, struct bounce_page *);
167 static bus_dmamap_t get_map_waiting(bus_dma_tag_t);
168 static void add_map_callback(bus_dmamap_t);
170 SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
171 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bounce_pages,
172 0, "Total bounce pages");
173 SYSCTL_INT(_hw_busdma, OID_AUTO, max_bpages, CTLFLAG_RD, &max_bounce_pages,
174 0, "Max bounce pages per bounce zone");
175 SYSCTL_INT(_hw_busdma, OID_AUTO, bounce_alignment, CTLFLAG_RD,
176 &bounce_alignment, 0, "Obey alignment constraint");
179 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
185 if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr) ||
186 (bounce_alignment && (paddr & (dmat->alignment - 1)) != 0))
187 && (dmat->filter == NULL ||
188 dmat->filter(dmat->filterarg, paddr) != 0))
192 } while (retval == 0 && dmat != NULL);
197 * Allocate a device specific dma_tag.
200 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
201 bus_size_t boundary, bus_addr_t lowaddr,
202 bus_addr_t highaddr, bus_dma_filter_t *filter,
203 void *filterarg, bus_size_t maxsize, int nsegments,
204 bus_size_t maxsegsz, int flags, bus_dma_tag_t *dmat)
206 bus_dma_tag_t newtag;
215 if (alignment & (alignment - 1))
216 panic("alignment must be power of 2");
219 if (boundary & (boundary - 1))
220 panic("boundary must be power of 2");
221 if (boundary < maxsegsz) {
222 kprintf("boundary < maxsegsz:\n");
228 /* Return a NULL tag on failure */
231 newtag = kmalloc(sizeof(*newtag), M_DEVBUF, M_INTWAIT);
233 newtag->parent = parent;
234 newtag->alignment = alignment;
235 newtag->boundary = boundary;
236 newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1);
237 newtag->highaddr = trunc_page((vm_paddr_t)highaddr) + (PAGE_SIZE - 1);
238 newtag->filter = filter;
239 newtag->filterarg = filterarg;
240 newtag->maxsize = maxsize;
241 newtag->nsegments = nsegments;
242 newtag->maxsegsz = maxsegsz;
243 newtag->flags = flags;
244 newtag->ref_count = 1; /* Count ourself */
245 newtag->map_count = 0;
246 newtag->segments = NULL;
247 newtag->bounce_zone = NULL;
249 /* Take into account any restrictions imposed by our parent tag */
250 if (parent != NULL) {
251 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
252 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
254 if (newtag->boundary == 0) {
255 newtag->boundary = parent->boundary;
256 } else if (parent->boundary != 0) {
257 newtag->boundary = MIN(parent->boundary,
262 newtag->alignment = MAX(parent->alignment, newtag->alignment);
265 if (newtag->filter == NULL) {
267 * Short circuit looking at our parent directly
268 * since we have encapsulated all of its information
270 newtag->filter = parent->filter;
271 newtag->filterarg = parent->filterarg;
272 newtag->parent = parent->parent;
274 if (newtag->parent != NULL)
278 if (newtag->lowaddr < ptoa(Maxmem))
279 newtag->flags |= BUS_DMA_BOUNCE_LOWADDR;
280 if (bounce_alignment && newtag->alignment > 1 &&
281 !(newtag->flags & BUS_DMA_ALIGNED))
282 newtag->flags |= BUS_DMA_BOUNCE_ALIGN;
284 if ((newtag->flags & BUS_DMA_COULD_BOUNCE) &&
285 (flags & BUS_DMA_ALLOCNOW) != 0) {
286 struct bounce_zone *bz;
290 error = alloc_bounce_zone(newtag);
293 bz = newtag->bounce_zone;
295 if (ptoa(bz->total_bpages) < maxsize) {
298 if (flags & BUS_DMA_ONEBPAGE) {
301 pages = atop(round_page(maxsize)) -
303 pages = MAX(pages, 1);
306 /* Add pages to our bounce pool */
307 if (alloc_bounce_pages(newtag, pages, flags) < pages)
310 /* Performed initial allocation */
311 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
316 kfree(newtag, M_DEVBUF);
323 bus_dma_tag_destroy(bus_dma_tag_t dmat)
326 if (dmat->map_count != 0)
329 while (dmat != NULL) {
330 bus_dma_tag_t parent;
332 parent = dmat->parent;
334 if (dmat->ref_count == 0) {
335 if (dmat->segments != NULL)
336 kfree(dmat->segments, M_DEVBUF);
337 kfree(dmat, M_DEVBUF);
339 * Last reference count, so
340 * release our reference
341 * count on our parent.
352 * Allocate a handle for mapping from kva/uva/physical
353 * address space into bus device space.
356 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
362 if (dmat->segments == NULL) {
363 KKASSERT(dmat->nsegments && dmat->nsegments < 16384);
364 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
365 dmat->nsegments, M_DEVBUF, M_INTWAIT);
368 if (dmat->flags & BUS_DMA_COULD_BOUNCE) {
369 struct bounce_zone *bz;
374 if (dmat->bounce_zone == NULL) {
375 error = alloc_bounce_zone(dmat);
379 bz = dmat->bounce_zone;
381 *mapp = kmalloc(sizeof(**mapp), M_DEVBUF, M_INTWAIT | M_ZERO);
383 /* Initialize the new map */
384 STAILQ_INIT(&((*mapp)->bpages));
387 * Attempt to add pages to our pool on a per-instance
388 * basis up to a sane limit.
390 if (dmat->flags & BUS_DMA_BOUNCE_ALIGN) {
391 maxpages = max_bounce_pages;
393 maxpages = MIN(max_bounce_pages,
394 Maxmem - atop(dmat->lowaddr));
396 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
397 || (dmat->map_count > 0
398 && bz->total_bpages < maxpages)) {
401 if (flags & BUS_DMA_ONEBPAGE) {
404 pages = atop(round_page(dmat->maxsize));
405 pages = MIN(maxpages - bz->total_bpages, pages);
406 pages = MAX(pages, 1);
408 if (alloc_bounce_pages(dmat, pages, flags) < pages)
411 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
413 dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
427 * Destroy a handle for mapping from kva/uva/physical
428 * address space into bus device space.
431 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
434 if (STAILQ_FIRST(&map->bpages) != NULL)
436 kfree(map, M_DEVBUF);
442 static __inline bus_size_t
443 check_kmalloc(bus_dma_tag_t dmat, const void *vaddr0, int verify)
445 bus_size_t maxsize = 0;
446 uintptr_t vaddr = (uintptr_t)vaddr0;
448 if ((vaddr ^ (vaddr + dmat->maxsize - 1)) & ~PAGE_MASK) {
449 kprintf("boundary check failed\n");
451 print_backtrace(-1); /* XXX panic */
452 maxsize = dmat->maxsize;
454 if (vaddr & (dmat->alignment - 1)) {
455 kprintf("alignment check failed\n");
457 print_backtrace(-1); /* XXX panic */
458 if (dmat->maxsize < dmat->alignment)
459 maxsize = dmat->alignment;
461 maxsize = dmat->maxsize;
467 * Allocate a piece of memory that can be efficiently mapped into
468 * bus device space based on the constraints lited in the dma tag.
470 * mapp is degenerate. By definition this allocation should not require
471 * bounce buffers so do not allocate a dma map.
474 bus_dmamem_alloc(bus_dma_tag_t dmat, void **vaddr, int flags,
479 /* If we succeed, no mapping/bouncing will be required */
482 if (dmat->segments == NULL) {
483 KKASSERT(dmat->nsegments < 16384);
484 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
485 dmat->nsegments, M_DEVBUF, M_INTWAIT);
488 if (flags & BUS_DMA_NOWAIT)
492 if (flags & BUS_DMA_ZERO)
495 if (BUS_DMAMEM_KMALLOC(dmat)) {
498 *vaddr = kmalloc(dmat->maxsize, M_DEVBUF, mflags);
502 * Check whether the allocation
503 * - crossed a page boundary
505 * Retry with power-of-2 alignment in the above cases.
507 maxsize = check_kmalloc(dmat, *vaddr, 0);
511 kfree(*vaddr, M_DEVBUF);
512 /* XXX check for overflow? */
513 for (size = 1; size <= maxsize; size <<= 1)
515 *vaddr = kmalloc(size, M_DEVBUF, mflags);
516 check_kmalloc(dmat, *vaddr, 1);
520 * XXX Use Contigmalloc until it is merged into this facility
521 * and handles multi-seg allocations. Nobody is doing
522 * multi-seg allocations yet though.
524 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
525 0ul, dmat->lowaddr, dmat->alignment, dmat->boundary);
533 * Free a piece of memory and it's allociated dmamap, that was allocated
534 * via bus_dmamem_alloc. Make the same choice for free/contigfree.
537 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
540 * dmamem does not need to be bounced, so the map should be
544 panic("bus_dmamem_free: Invalid map freed");
545 if (BUS_DMAMEM_KMALLOC(dmat))
546 kfree(vaddr, M_DEVBUF);
548 contigfree(vaddr, dmat->maxsize, M_DEVBUF);
551 static __inline vm_paddr_t
552 _bus_dma_extract(pmap_t pmap, vm_offset_t vaddr)
555 return pmap_extract(pmap, vaddr);
557 return pmap_kextract(vaddr);
561 * Utility function to load a linear buffer. lastaddrp holds state
562 * between invocations (for multiple-buffer loads). segp contains
563 * the segment following the starting one on entrace, and the ending
564 * segment on exit. first indicates if this is the first invocation
568 _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
570 void *buf, bus_size_t buflen,
571 bus_dma_segment_t *segments,
575 vm_paddr_t *lastpaddrp,
580 vm_paddr_t paddr, nextpaddr;
581 bus_dma_segment_t *sg;
586 map = &nobounce_dmamap;
589 if (dmat->flags & BUS_DMA_ALIGNED)
590 KKASSERT(((uintptr_t)buf & (dmat->alignment - 1)) == 0);
594 * If we are being called during a callback, pagesneeded will
595 * be non-zero, so we can avoid doing the work twice.
597 if ((dmat->flags & BUS_DMA_COULD_BOUNCE) &&
598 map != &nobounce_dmamap && map->pagesneeded == 0) {
599 vm_offset_t vendaddr;
602 * Count the number of bounce pages
603 * needed in order to complete this transfer
605 vaddr = (vm_offset_t)buf;
606 vendaddr = (vm_offset_t)buf + buflen;
608 while (vaddr < vendaddr) {
609 paddr = _bus_dma_extract(pmap, vaddr);
610 if (run_filter(dmat, paddr) != 0)
612 vaddr += (PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK));
616 /* Reserve Necessary Bounce Pages */
617 if (map->pagesneeded != 0) {
618 struct bounce_zone *bz;
620 bz = dmat->bounce_zone;
622 if (flags & BUS_DMA_NOWAIT) {
623 if (reserve_bounce_pages(dmat, map, 0) != 0) {
629 if (reserve_bounce_pages(dmat, map, 1) != 0) {
630 /* Queue us for resources */
633 map->buflen = buflen;
636 &dmat->bounce_zone->bounce_map_waitinglist,
640 return (EINPROGRESS);
646 KKASSERT(*segp >= 1 && *segp <= nsegments);
648 sg = &segments[seg - 1];
650 vaddr = (vm_offset_t)buf;
651 nextpaddr = *lastpaddrp;
652 bmask = ~(dmat->boundary - 1); /* note: will be 0 if boundary is 0 */
654 /* force at least one segment */
661 paddr = _bus_dma_extract(pmap, vaddr);
662 size = PAGE_SIZE - (paddr & PAGE_MASK);
665 if (map->pagesneeded != 0 && run_filter(dmat, paddr)) {
667 * note: this paddr has the same in-page offset
668 * as vaddr and thus the paddr above, so the
669 * size does not have to be recalculated
671 paddr = add_bounce_page(dmat, map, vaddr, size);
675 * Fill in the bus_dma_segment
681 } else if (paddr == nextpaddr) {
691 nextpaddr = paddr + size;
694 * Handle maxsegsz and boundary issues with a nested loop
700 * Limit to the boundary and maximum segment size
702 if (((nextpaddr - 1) ^ sg->ds_addr) & bmask) {
703 tmpsize = dmat->boundary -
704 (sg->ds_addr & ~bmask);
705 if (tmpsize > dmat->maxsegsz)
706 tmpsize = dmat->maxsegsz;
707 KKASSERT(tmpsize < sg->ds_len);
708 } else if (sg->ds_len > dmat->maxsegsz) {
709 tmpsize = dmat->maxsegsz;
715 * Futz, split the data into a new segment.
717 if (seg >= nsegments)
719 sg[1].ds_len = sg[0].ds_len - tmpsize;
720 sg[1].ds_addr = sg[0].ds_addr + tmpsize;
721 sg[0].ds_len = tmpsize;
731 } while (buflen > 0);
737 *lastpaddrp = nextpaddr;
740 if (error && (dmat->flags & BUS_DMA_COULD_BOUNCE) &&
741 map != &nobounce_dmamap) {
742 _bus_dmamap_unload(dmat, map);
743 return_bounce_pages(dmat, map);
749 * Map the buffer buf into bus space using the dmamap map.
752 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
753 bus_size_t buflen, bus_dmamap_callback_t *callback,
754 void *callback_arg, int flags)
756 vm_paddr_t lastaddr = 0;
757 int error, nsegs = 1;
762 * Follow old semantics. Once all of the callers are fixed,
763 * we should get rid of these internal flag "adjustment".
765 flags &= ~BUS_DMA_NOWAIT;
766 flags |= BUS_DMA_WAITOK;
768 map->callback = callback;
769 map->callback_arg = callback_arg;
772 error = _bus_dmamap_load_buffer(dmat, map, buf, buflen,
773 dmat->segments, dmat->nsegments,
774 NULL, flags, &lastaddr, &nsegs, 1);
775 if (error == EINPROGRESS)
778 callback(callback_arg, dmat->segments, nsegs, error);
783 * Like _bus_dmamap_load(), but for mbufs.
786 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
788 bus_dmamap_callback2_t *callback, void *callback_arg,
795 * Follow old semantics. Once all of the callers are fixed,
796 * we should get rid of these internal flag "adjustment".
798 flags &= ~BUS_DMA_WAITOK;
799 flags |= BUS_DMA_NOWAIT;
801 error = bus_dmamap_load_mbuf_segment(dmat, map, m0,
802 dmat->segments, dmat->nsegments, &nsegs, flags);
804 /* force "no valid mappings" in callback */
805 callback(callback_arg, dmat->segments, 0, 0, error);
807 callback(callback_arg, dmat->segments, nsegs,
808 m0->m_pkthdr.len, error);
814 bus_dmamap_load_mbuf_segment(bus_dma_tag_t dmat, bus_dmamap_t map,
816 bus_dma_segment_t *segs, int maxsegs,
817 int *nsegs, int flags)
823 KASSERT(maxsegs >= 1, ("invalid maxsegs %d", maxsegs));
824 KASSERT(maxsegs <= dmat->nsegments,
825 ("%d too many segments, dmat only supports %d segments",
826 maxsegs, dmat->nsegments));
827 KASSERT(flags & BUS_DMA_NOWAIT,
828 ("only BUS_DMA_NOWAIT is supported"));
830 if (m0->m_pkthdr.len <= dmat->maxsize) {
832 vm_paddr_t lastaddr = 0;
837 for (m = m0; m != NULL && error == 0; m = m->m_next) {
841 error = _bus_dmamap_load_buffer(dmat, map,
844 NULL, flags, &lastaddr,
846 if (error == ENOMEM && !first) {
848 * Out of bounce pages due to too many
849 * fragments in the mbuf chain; return
858 KKASSERT(*nsegs <= maxsegs && *nsegs >= 1);
864 KKASSERT(error != EINPROGRESS);
869 * Like _bus_dmamap_load(), but for uios.
872 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
874 bus_dmamap_callback2_t *callback, void *callback_arg,
878 int nsegs, error, first, i;
885 * Follow old semantics. Once all of the callers are fixed,
886 * we should get rid of these internal flag "adjustment".
888 flags &= ~BUS_DMA_WAITOK;
889 flags |= BUS_DMA_NOWAIT;
891 resid = (bus_size_t)uio->uio_resid;
894 if (uio->uio_segflg == UIO_USERSPACE) {
898 KASSERT(td != NULL && td->td_proc != NULL,
899 ("bus_dmamap_load_uio: USERSPACE but no proc"));
900 pmap = vmspace_pmap(td->td_proc->p_vmspace);
909 for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
911 * Now at the first iovec to load. Load each iovec
912 * until we have exhausted the residual count.
915 resid < iov[i].iov_len ? resid : iov[i].iov_len;
916 caddr_t addr = (caddr_t) iov[i].iov_base;
918 error = _bus_dmamap_load_buffer(dmat, map, addr, minlen,
919 dmat->segments, dmat->nsegments,
920 pmap, flags, &lastaddr, &nsegs, first);
927 /* force "no valid mappings" in callback */
928 callback(callback_arg, dmat->segments, 0, 0, error);
930 callback(callback_arg, dmat->segments, nsegs,
931 (bus_size_t)uio->uio_resid, error);
937 * Release the mapping held by map.
940 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
942 struct bounce_page *bpage;
944 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
945 STAILQ_REMOVE_HEAD(&map->bpages, links);
946 free_bounce_page(dmat, bpage);
951 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
953 struct bounce_page *bpage;
955 if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
957 * Handle data bouncing. We might also
958 * want to add support for invalidating
959 * the caches on broken hardware
962 case BUS_DMASYNC_PREWRITE:
963 while (bpage != NULL) {
964 bcopy((void *)bpage->datavaddr,
965 (void *)bpage->vaddr,
967 bpage = STAILQ_NEXT(bpage, links);
969 dmat->bounce_zone->total_bounced++;
972 case BUS_DMASYNC_POSTREAD:
973 while (bpage != NULL) {
974 bcopy((void *)bpage->vaddr,
975 (void *)bpage->datavaddr,
977 bpage = STAILQ_NEXT(bpage, links);
979 dmat->bounce_zone->total_bounced++;
982 case BUS_DMASYNC_PREREAD:
983 case BUS_DMASYNC_POSTWRITE:
991 alloc_bounce_zone(bus_dma_tag_t dmat)
993 struct bounce_zone *bz, *new_bz;
995 KASSERT(dmat->bounce_zone == NULL,
996 ("bounce zone was already assigned"));
998 new_bz = kmalloc(sizeof(*new_bz), M_DEVBUF, M_INTWAIT | M_ZERO);
1000 lwkt_gettoken(&bounce_zone_tok);
1002 /* Check to see if we already have a suitable zone */
1003 STAILQ_FOREACH(bz, &bounce_zone_list, links) {
1004 if (dmat->alignment <= bz->alignment &&
1005 dmat->lowaddr >= bz->lowaddr) {
1006 lwkt_reltoken(&bounce_zone_tok);
1008 dmat->bounce_zone = bz;
1009 kfree(new_bz, M_DEVBUF);
1016 spin_init(&bz->spin);
1018 STAILQ_INIT(&bz->bounce_page_list);
1019 STAILQ_INIT(&bz->bounce_map_waitinglist);
1020 bz->free_bpages = 0;
1021 bz->reserved_bpages = 0;
1022 bz->active_bpages = 0;
1023 bz->lowaddr = dmat->lowaddr;
1024 bz->alignment = round_page(dmat->alignment);
1025 ksnprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1027 ksnprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1028 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1030 lwkt_reltoken(&bounce_zone_tok);
1032 dmat->bounce_zone = bz;
1034 sysctl_ctx_init(&bz->sysctl_ctx);
1035 bz->sysctl_tree = SYSCTL_ADD_NODE(&bz->sysctl_ctx,
1036 SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1038 if (bz->sysctl_tree == NULL) {
1039 sysctl_ctx_free(&bz->sysctl_ctx);
1040 return 0; /* XXX error code? */
1043 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1044 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1045 "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1046 "Total bounce pages");
1047 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1048 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1049 "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1050 "Free bounce pages");
1051 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1052 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1053 "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1054 "Reserved bounce pages");
1055 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1056 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1057 "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1058 "Active bounce pages");
1059 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1060 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1061 "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1062 "Total bounce requests");
1063 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1064 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1065 "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1066 "Total bounce requests that were deferred");
1067 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1068 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1069 "reserve_failed", CTLFLAG_RD, &bz->reserve_failed, 0,
1070 "Total bounce page reservations that were failed");
1071 SYSCTL_ADD_STRING(&bz->sysctl_ctx,
1072 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1073 "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1074 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1075 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1076 "alignment", CTLFLAG_RD, &bz->alignment, 0, "");
1082 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages, int flags)
1084 struct bounce_zone *bz = dmat->bounce_zone;
1085 int count = 0, mflags;
1087 if (flags & BUS_DMA_NOWAIT)
1092 while (numpages > 0) {
1093 struct bounce_page *bpage;
1095 bpage = kmalloc(sizeof(*bpage), M_DEVBUF, M_INTWAIT | M_ZERO);
1097 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
1101 if (bpage->vaddr == 0) {
1102 kfree(bpage, M_DEVBUF);
1105 bpage->busaddr = pmap_kextract(bpage->vaddr);
1108 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1109 total_bounce_pages++;
1120 /* Assume caller holds bounce zone spinlock */
1122 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1124 struct bounce_zone *bz = dmat->bounce_zone;
1127 pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1128 if (!commit && map->pagesneeded > (map->pagesreserved + pages)) {
1129 bz->reserve_failed++;
1130 return (map->pagesneeded - (map->pagesreserved + pages));
1133 bz->free_bpages -= pages;
1135 bz->reserved_bpages += pages;
1136 KKASSERT(bz->reserved_bpages <= bz->total_bpages);
1138 map->pagesreserved += pages;
1139 pages = map->pagesneeded - map->pagesreserved;
1145 return_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
1147 struct bounce_zone *bz = dmat->bounce_zone;
1148 int reserved = map->pagesreserved;
1149 bus_dmamap_t wait_map;
1151 map->pagesreserved = 0;
1152 map->pagesneeded = 0;
1159 bz->free_bpages += reserved;
1160 KKASSERT(bz->free_bpages <= bz->total_bpages);
1162 KKASSERT(bz->reserved_bpages >= reserved);
1163 bz->reserved_bpages -= reserved;
1165 wait_map = get_map_waiting(dmat);
1169 if (wait_map != NULL)
1170 add_map_callback(map);
1174 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1177 struct bounce_zone *bz = dmat->bounce_zone;
1178 struct bounce_page *bpage;
1180 KASSERT(map->pagesneeded > 0, ("map doesn't need any pages"));
1183 KASSERT(map->pagesreserved > 0, ("map doesn't reserve any pages"));
1184 map->pagesreserved--;
1188 bpage = STAILQ_FIRST(&bz->bounce_page_list);
1189 KASSERT(bpage != NULL, ("free page list is empty"));
1190 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1192 KKASSERT(bz->reserved_bpages > 0);
1193 bz->reserved_bpages--;
1195 bz->active_bpages++;
1196 KKASSERT(bz->active_bpages <= bz->total_bpages);
1200 bpage->datavaddr = vaddr;
1201 bpage->datacount = size;
1202 STAILQ_INSERT_TAIL(&map->bpages, bpage, links);
1203 return bpage->busaddr;
1207 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1209 struct bounce_zone *bz = dmat->bounce_zone;
1212 bpage->datavaddr = 0;
1213 bpage->datacount = 0;
1217 STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1220 KKASSERT(bz->free_bpages <= bz->total_bpages);
1222 KKASSERT(bz->active_bpages > 0);
1223 bz->active_bpages--;
1225 map = get_map_waiting(dmat);
1230 add_map_callback(map);
1233 /* Assume caller holds bounce zone spinlock */
1235 get_map_waiting(bus_dma_tag_t dmat)
1237 struct bounce_zone *bz = dmat->bounce_zone;
1240 map = STAILQ_FIRST(&bz->bounce_map_waitinglist);
1242 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1243 STAILQ_REMOVE_HEAD(&bz->bounce_map_waitinglist, links);
1244 bz->total_deferred++;
1253 add_map_callback(bus_dmamap_t map)
1256 /* XXX callbacklist is not MPSAFE */
1259 STAILQ_INSERT_TAIL(&bounce_map_callbacklist, map, links);
1260 busdma_swi_pending = 1;
1265 panic("%s uncoded", __func__);
1276 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1277 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1279 bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
1280 map->callback, map->callback_arg, /*flags*/0);